Carotenoids are generally only soluble to any extent in lipid materials or organic solvents. Many of their applications for use, however, make it desirable that they are contained in aqueous based systems for the purposes of providing a safe source of vitamin A, colourisation (particularly food products which are generally in aqueous based materials) or as a powdered product in special preparations which are based on aqueous materials.
To overcome the virtual insolubility of carotenoids in water, so called water dispersible forms of carotenoid products are manufactured for use. They are a significant part of the economic market for carotenoids.
Recently, there has been a consumer driven preference for natural products in the market place and this has also been true for carotenoid products. The demand for products containing natural beta-carotene (a carotenoid) has grown substantially over the last five years. Natural beta-carotene is derived from certain animals, plants and microorganisms, such as the alga Dunaliella salina. However, it is inconsistent in the eyes of consumers to make a water dispersible natural carotenoid product using, for example, beta-carotene extracted from Dunaliella salina, and then to use synthetic raw materials in the manufacture of the water dispersible material. Consequently, there is a need to provide a completely natural product of water dispersible carotenoids in both a liquid emulsion and dried product form which represent the main forms in which these products are sold.
Emulsions are stable mixtures of two or more immiscible liquids held in suspension by stabilizers and small percentages of substances called emulsifiers.
Certain emulsions occur naturally. These include milk, cream, avocado, egg yolk and nuts. These emulsions contain fine dispersions of natural lipid material which are stabilized in two ways. First, by small sized droplets of fat which occur within the cell structure and cannot coalesce into larger particles due to the solidity or very high viscosity of the product. Avocado and nuts are examples of this type of emulsion. Secondly, in more fluid products with reduced viscosity, the small fat droplets are stabilized within the aqueous structure by naturally present emulsifying agents or biochemicals and by polymeric molecules of carbohydrates, proteins and lipids or combinations of all three often where the molecules are chemically bonded together which restrict the coalescing of the small lipid globules.
In more recent times these stabilizing agents have been extracted from the natural materials to provide concentrated sources of emulsifiers and stabilizers which can be used more generally for food and other biological emulsions. For example, in the preparation of salad dressing products or mayonnaise, starches, egg yolk, microbial and vegetable isolates have been selected to assist in stabilizing vegetable oils to provide a pleasing mouth texture and flavour for culinary purposes. Although the natural materials are quite satisfactory for many applications there have also been chemically modified stabilizers and emulsifiers produced which can make more stable emulsions. The chemically modified stabilizers and emulsifiers have the disadvantage that they are produced from synthetic chemical processes and for that reason they are not favoured by certain manufacturers of food products.
Previous emulsions of carotenoids have normally incorporated these chemically modified stabilizing agents for the production of carotenoid emulsions and dried water dispersible products.
It is a general requirement that carotenoids be protected against oxidation and that the liquid preparations be preserved against microbiological spoilage. For these reasons, synthetic antioxidants and synthetic preservatives have also been used in carotenoid liquid emulsions and dried powders.
The object of the invention is to provide a carotenoid composition derived principally from natural sources and a method of preparing these compositions employing a natural emulsion system to create oil in water dispersions. To achieve this result, certain mechanical and physical processes are used to provide a complete process such that a water dispersible powder and liquid emulsion product can be produced without the need for synthetic or unnatural ingredients at all.